Piston ring



March 14, 1944.

M. O. TEETOR PISTON RING Filed Feb. 18, 1939 2 Sheets-'Sheet 2 Patented Mar. 14, 1944 l ates.

uNiTED STATES PATENT OFFICE Pis'roN ame Macy 0. Teetor, Newcastle, Ind., assignor to The Perfect Circle Company, Hagerstown, Ind., a corporation of Indiana Application February 1s, 1939, serial No. 257,082

'7 Claims.

My invention relates to piston rings adapted to be mounted in the ring groove in a piston of an interna1 combustion engine having a cylinder wall to be engaged, and it has to do particularly with segmental rings of the foregoing character adapted for reducing oil consumption. v

One of the objects of my invention is to provide an improved ring of the foregoing character which is of simple construction, is inexpensive to manufacture, and which is adapted to perform its intended functions in a highly eflicient manner.

Another object is to provide an improved segmental ring which includes a pair of thin, at, split, -ring-like sections or rails that are spaced apart axially by a spring section or member which is adapted to expand the rails radially.

A further object is to provide an improved spring expander which takes the form of aonepiece, band-like spring member having certain portions with parallel side edges adapted to be disposed between and engage parallel facing sides of the Arails for spacing them apartwithout exerting axial pressurethereon, and other portions adapted to engage the inner circumferential edges of the rails to expand them radially without affecting the axial position of the rails as provided by the spacing portions.

Other objects and advantages will become apparent as this description progresses and by referen'ce to the drawings whereiny.Figure 1 is a horizontal section through the groove of a piston and illustrating ring structure embodying my invention mounted therein;

Fig. 2 is an' enlarged sectional view loi the structure shown in Fig. 1, the same being illustrated in operating relation to a cylinder Wall;

Fig. 3 is an assembly view of the ring structure shown in Figs. 1 and 2; and

Fig. 4 is a fragmental, side elevational View of the ring structure shown in the previous iigures, and further illustrating the manner of interlocking the ring expander sections.

The ring structure shown in the drawings is adapted to be mounted in a groove I0 (Figs. 1 and 2) in a piston I I of an internal combustion engine having a cylinder I2 in which the piston oper- The piston may take any suitable form, and it is provided with an annular series of oil holes I3 leading through the piston wall from the bottom of the ring groove I0 for drainage of oil from the latter into the engine crank case (not shown). segmental form, including a pair of rails I4, I5 (Figs. 2 and 3) and a spacer-expander section I6.

The ring structure shown is ofy The rails or segments I4, I5 (Figs. 2 and 3) are of similar construction, each being formed from a thin, preferably steel, material to a flat. ring-like shape split at I1 for a purpose that will be well understood. Such rails vare adapted to be disposed along the opposite sides of the ring groove III with their facing sides normally disposed in parallel relation. Also, the rails I4, I5 are of such width that, when they are installedv in the ring groove I0 and the piston II is inserted in the cylinder I2, their thin outer peripheries engag the cylinder wall under some tension.

The spacer-expander section I6 takes the form of a band-like spring member of polygonal-like shape having side portions I8 joined at their ends 4by rounded or humped, spring-like portions I9.

The expander section is of substantially the saine width throughout as the ring structure so that it is confined between the rails I4, I5 and the bottom of the ring groove I0, with the humps I9 engaging the inner peripheries of the rails I4, I5 and acting as spring portions for expanding the rails radially toward the cylinder wall. rIhe expander sides' I8, adjacent their central portions, seat against the bottom of the ring groove I0, thereby supporting the expander section for the rail expanding action just described.

The expander section or spring member I6 also 1 spaces apart the rails I4, I5 Without exerting any axial expanding action thereon and without affecting they axial position of the rail sections as they are expanded radially. This spacing is accomplished by providing the spring member I6 through the ring structure and back to the en- 'gine crank case through the piston holes I3 byl passing'over and under the rails I4, I5. The rails I 4, I5 normally have sufficient clearance with respect to the side walls of the ring groove I0 to permit oil collected between the rails to readily pass the structure under the influence of the hydraulic action that takes place in the operaticn'of the structure, and by which there is a tedency for oil to be thrown, forced or pumped,

so to speak, toward the opposite side walls oi the ring groove. Oil drainage past the expander 1 section i6 may take place through the openings 2| formed in making the spacing-.humps or portions 20 or, if desired, additionalv circumferentially spaced openiigs may be formed in the spacer section, or the side edges thereof may be"l recessed to more readily permit passage of oil at those points.- v

'. It is desirable, for best operation of my ring structure, that the railI joints I1' and the joint 22 formed by the free ends I6* andlib of the ex- Y pander section I6 be maintained substantially in I alignment with each other. To insurethis re-y lationship, and toavoid relative creepage of the sections during operation, I interlock. the' ends I6* and I8b of the expander section with the split ends of the rail sections. Specifically, the expander end portions lgand 16" take the form of end parts 23 and 23* bent radially outward and terminating inl reversely bent-parts 2l and 24".

Ihe reversely bent parts 2|, Pare formed to the same width as'the expander spacing portions 20,

Y and the splitend portionspf the rails Il, I are .adapted to seat thereonvioresxial support. The upper edge of the radial patz of the righthand end .portion I6 (Figs. 3 and 4) extends ilush with the upper edge ,onf/the expander section, while the corresponding up'penportion of the left-hand end part 211s cut away to a4 point substantially in the same plane as thel upper edge of the spacing portions 20. With this arrangement, the left-hand endof the upper rail Il may pass the left-hand end part 23 to abut the right# hand endpart 23, while the right-hand end of such upper railcannot pass the right-handend part 23. In this way, the right-hand end part `wardly from only said first mentioned spaced l portions and projecting between said rails, and having parallel side edges engaging the facing sides ofA said rails to space the latter apart at a flied axial distance thereon.

2. A spacer-expander for piston ring structure lhaving thin, split rails having parallel sides axially spaced apart with their outer peripheries adapted to engage a cylinder wall, which comprises a band-like spring member of polygonallike shape, the sides of which are adapted to seat upon lthe bottom of a ring groove, hump-like spring portions connecting said sides at their ends and adapted to engage the inner peripheries oi' the rails to radially expand the same, and

lother portions projecting radially outwardly from said sides farther than said hump-like conn ecting portions, said other portions being 23",l is disposed in the joint of the upper'rail M thereby preventing any material circumferential movement'of the latter relative to the expander section. The lower edges of the expander endl parts 23 and 2 3* are formed similarly to the upper edge portions thereof except that they are reversed so 'that the lower edge of the right-hand end part`23 is cut away to the level of the lower sides of the spacing portions 20 and the lower edge of the leftehand end part 23=is flush with the lower edge of thejexpander.` Thusly, the

is interlocked with the left-hands 50.

lower rail il expander end part 23 in the same manner as the upper rail il is interlocked with the right-hand end'part 23s.

I believe that the loperation and advantages of my invention will be well understood from the foregoing description. The` rails may be quite thin so that thin, outer edge portions or peripheries engage the cylinder wall. By: spacing apart the rails with a one-piece spring expander, L

adapted to extend between and engage said rails to space said rails axially apart a ilxed distance.

3. A spacer-expander for piston ring structure having thin, split rails with substantially parallel facing sides and axially spaced apart with their outer peripheries adapted to engage a cylinder wall, which comprises a band-like spring member of polygonal-like shape, the sidesA of which are adapted to seat upon the bottom of a ring groove, hump-like spring portions connecting said sides at their ends and adapted to engage the inner peripheries oi' the rails to radiallylexpand the same, and other portions intermediate said hump-like spring portions projecting outwardly `from said sides and having parallel side edges adapted to extend between and engage the facing sides of the rails to space them apart axially a ilxed distance.

4. @spacer-expander for piston ring structure l'iaving thin, split rails axially spaced apart with their outer peripheries adapted to engage a cylinder wall, which comprises a one-piece polygonall-y shaped springvmember having side portions joined together 'at their ends by rounded hump-like portions, said side and hump-like portions being of substantially the axial width 'i' the vrin'ggroove in which said spacer-expander s to be used with the hump portions adapted engage the inner peripheries o1' the ring rails' radially expand the same, and other portions 'of an axial width substantially equal to the normal axial spacing of the ring rails struck from said side portions and adapted to extend ybetween and engage the ring rails to space said l .ring rails apart axially.

I provide a simple and inexpensive construction which is adapted to perform its intended functions in a highly efllclent manner. l ,5- I claim:

"1'. A piston ringa ring groove in -a pistonof an internal com bustion engine having a cylinder wall to be enstructure adapted for use in gaged, comprising apair of thin, split rails having parallel sides adapted to be disposed along the opposite sides of the ring groove, anda spring expander oir ribbon steel of substantially uniform thickness having circumferentially spaced portions adapted to engage the bottom of the groove,

circumferentially spaced portions located between said first` mentioned spacedf'portions and en-v gaging the inner peripheries of said, rfail's, and circumferentially spaced portions extending out- 5. A spacer-expander for use with a pair of piston ring rails to space said rails axially apart and to radially expandv said rails comprising: a thin at steel ribbon bent to generally polygonal form to provide circumferentially spaced side portions connected by hump portions, said side portions being adapted to engage the-bottom of a ring groove and said hump portions being adapted to engage the inner periphery of said said side portions having a part thereof struck out to formv a rail-spacing portion, and

said rail-spacing portions extending radially outwardly farther than said hump portions and being adapted to extend between said rails to axially space said rails apart.

6. A spacer-.expander for use with a pair ofl piston ring rails to space 'said rails axially apart and to radially expand said rails comprising: a

thin flat steel ribbon bent to generally polygonal form to provide `circumferentially spaced side portions connected by hump portions, said side portions being adapted to engage the bottom of a ring groove and said hump portions having crests adapted to engage the inner periphery of said rails, each of said side portions having an outwardly bowed portion extending therefrom and adapted to serve as rail-spacing portions, and the crests of said outwardly bowed portions extending radially outwardly farther than the crests of said hump portions.

7. A multi-piece piston oil control ring coinprising a coaxial assembly of a pair of substantially at relatively thin annular cylinder wall engaging ring members having `spaced ends permitting radial expansion and contraction of the members, and an annular sinuous marcel expanden' member mounted interiorly of said ring members having inwardly extending undulated portions for engaging the bottom of the ring groove and outwardly extending undulated portions for engaging the inner periphery of said ring members and being formed with spacing elements projecting outwardly from said expander member at the inwardly extending undulated portionsA4 thereof, said outwardly projecting spacing elements engaging between said rings for holding the same in spacedr apart substantially parallel relation, the forming of said outwardly projecting spacing elements leaving openings through said expander at said spacing elementsrfor passage of oil.

, MACY O. TEETOR. 

